JOHNSON CONTROLS
20
FORM 160.67-O2
ISSUE DATE: 10/9/2020
SECTION 2 - PRE-STARTUP AND SYSTEM OPERATING PROCEDURES
Thermal expansion and contraction, which occurs dur-
ing warming up and cooling down, helps break loose
the foreign material inside the piping. Hammering
around any welded joints in the piping will also help to
break loose foreign material
The above procedures of warm-up, blow-down and
cool-off should be repeated as many times as neces-
sary to clean all foreign materials out of the piping. To
check for clean piping, a target should be placed about
two feet away from the blow-down opening so that the
steam will hit the target, and any solids in the steam
will become embedded in the target. Plywood, alumi-
num and polished stainless steel are commonly used
target materials. Piping can be considered clean when
no embedded particles and indentations are found in
the target after a 15 second blow-down.
Pieces of weld metal, large pieces of scale,
nuts, and other materials are commonly
present in newly erected steam lines. For
that reason it is necessary to emphasize
the importance of blowing out all steam
lines with live steam before connecting
the turbine. Failure to do so may result
in damage to the strainer or more serious
damage such as bent or failed blades.
INSPECT AND CLEAN STEAM STRAINERS
The turbine on the standard YST chiller has a built-in
type of strainer. This strainer should be inspected and
cleaned periodically and checked for possible damage.
A steam strainer affords some measure of protection
against foreign material passing through the nozzles
and blades, but it cannot be expected to stop heavy ob-
jects that move through the steam line at high velocity.
The element of the steam strainer in the steam line up-
stream of the governor valve should be inspected peri-
odically, and cleaned if necessary, to avoid excessive
steam pressure drop due to a clogged strainer screen.
Large pressure drops may not only reduce the turbine
load carrying capacity, but may result in a rupture of
the strainer element.
INSPECT AND CLEAN WATER STRAINERS
Any strainers in the water inlet lines for the compres-
sor oil cooler, turbine oil cooler (if supplied), and the
steam condenser vacuum pump sealing water should
be inspected and cleaned periodically and checked for
possible damage.
INSPECT AND CLEAN THE TURBINE
Before a turbine is operated, certain parts must be
cleaned to remove the effects of transit and storage.
Protective mylar sheets installed between the journal
bearing and the shaft journal must be removed prior to
rotating the shaft. (See FLUSH THE TURBINE LUBE
SYSTEM below for instructions) Bearing caps are eas-
ily removed. The interior of the bearing cases must be
inspected for dust or other grit. If any is present, the
interior of the bearing cases must be flushed with kero-
sene or similar solvent.
Mechanical governor parts should be thoroughly
washed with a spray of non-acetate solvent to remove
adhering dust particles. The interior of the turbine cas-
ing should be thoroughly cleaned so the exhaust sys-
tem will not become contaminated with dirt. This can
be done easily with a water hose through the exhaust
opening. Valve stems and other exposed machined
surfaces should be cleaned with solvent to remove pro-
tective grease and/or dirt.
Exposed machined parts have been masked prior to
painting. This masking serves as added protection
during shipment and is not removed before shipping.
Masking must be removed during the cleaning proce-
dure.
All loose parts (such as loose piping, etc.) should be
cleaned and installed. Turbines packed for export, or
protected for long storage periods may need to be com-
pletely dismantled and cleaned to remove all protective
grease and flushing compound. YORK will provide
specific instructions for turbines requiring complete
dismantling.
FLUSH THE TURBINE LUBE SYSTEM
(PRESSURE LUBRICATION TURBINE ONLY)
Flushing the oil circulation system on a turbine sup-
plied with an auxiliary oil pump is recommended be-
fore starting a new turbine (or one that has been in stor-
age for a long time). On a new turbine, remove the
mylar protection that stabilizes the shaft during ship-
ment. To do this, remove the upper half of the bearing
housing, remove the upper half of the bearing and re-
move all (above and below) pieces of mylar protection
(above and below) from the shaft. This must be done
at both the steam and exhaust end bearings. Leave the
upper halves of both bearings out to allow for more
volume of oil to flow during the flush. Reseal the up-
per bearing housing cover and replace the bolting.
